WUPPE was designed to
obtain simultaneous spectra and polarization
measurements from 1400 to 3300Å. WUPPE has a 0.5m f/10
classical Cassegrain
telescope (area = 1,800 square centimeters,
279 square inches) and a
spectropolarimeter, with a field of view of 3.3 by
4.4 arc-minutes and a resolution of 6 angstroms.
The telescope
feeds light to a low resolution spectrometer equipped with
various polarimetric analyzers.
The
spectrometer is a modified Monk-Gilleson spectrometer:
two rotating wheels are used to select the focal plane aperture
and the polarimetric analyzer;
a magnesium fluoride Wollaston
polarizing beam-splitter placed between the aperture and the relay
mirror splits the beam into two orthogonally-polarized spectra
which fall on the detector.
The
detector consists of dual Reticon self-scanning linear arrays of 1024
pixel photodiodes (to detect both beams simultaneously)
coupled by fiber optics to a microchannel plate intensifier with a
cesium-telluride photocathode. A charge-coupled device camera is
provided for target acquisition and for viewing the aperture during a
measurement.
The
focal plane scale is 26 arcsec/mm and the dispersion is 78 Å/mm, blaze
at 2000 Angstroms. A set of halfwave plates at 6 different angles
provided spectropolarimetric modulation with 5 angstrom resolution on
point sources through apertures from 6 to 40 arcsec. A "Lyot" analyzer
was used to provide 50-100 angstrom spectropolarimetric resolution on
faint point targets and diffuse nebulae.